对2008年12月青岛大学附属医院心肾免疫儿科收治并随访至2020年3月的1例以肾病综合征起病的常染色体显性遗传Alport综合征患儿的临床特点、基因检测结果及家系调查进行分析。先证者，女，11个月以肾炎型肾病综合征起病，表现为激素耐药，环孢素口服及环磷酰胺治疗均无明显疗效；发病2年完善肾组织活检，光镜示肾小球节段系膜增生性病变，Ⅳ型胶原染色α3肾小球基底膜(GBM)、肾小管基底膜(TBM)缺失，α5 GBM缺失；电镜示GBM不均一，基膜致密层明显分层、撕裂，呈"花边状"改变，节段基膜内皮下疏松、增宽。其父在患儿起病10年后才出现镜下血尿，祖母在患儿诊断Alport综合征后发现无症状性血尿和蛋白尿。基因检测：患儿COL4A4基因c.1715delG杂合变异(p.G572Vfs*81)，其父、祖母该位点为杂合变异，其母及妹妹无变异。提示常染色体显性遗传Alport综合征表现高度临床异质性，其发病率可能高于传统认知。

The clinical characteristics, mutation analysis results, and family tree of a patient with autosomal dominant Alport syndrome (ADAS), who had nephrotic syndrome as the first manifestation were examined.The proband was a 11-month-old girl who presented with nephrotic syndromes and gross hematuria.During the treatment course, the patient had steroid resistance and a poor response to Cyclosporine and Cyclophosphamide pulse therapy.Renal biopsy was performed 2 years after disease onset.Under the light microscopy, glomerular segmental mesangio-proliferative lesions were observed.The staining of type Ⅳ collagen showed the loss of the α3 chain in the glomerular basement membrane (GBM) and tubular basement membrane, and α5 chain loss in GBM.Electron microscopy showed uneven thickness of GBM, with obviously delaminated and tearing dense basement membrane (BM) layer, showing a typical lace-like change.The segmental BM was loosened and widened.Her father did not develop microscopic hematuria until 10 years later, while her grandmother had asymptomatic hematuria and proteinuria when the proband was diagnosed.A new mutation in the COL4A4 gene was found in the proband, namely c. 1715delG (p.G572Vfs * 81). Her father and grandmother carried the same mutation, but her mother and sister did not have.The clinical manifestation of ADAS is clinically heterogeneous and its incidence may be higher than what we have expected.